Furiosa’s Cat Feeder

The trick is to be smarter than the animal with a brain the size of a walnut

“This will be great,” I thought to myself. “I’ll get one of those high-tech automated cat feeders!”

Wait, I should back up a bit. You see, the four-legged tenant of Dunki Freehold, who goes by Sprocket H.G. Shopcat, eats twice a day. She gets delicious healthy wet food in the morning, and less-good-for-her but nice-for-lazy-human dry food in the evening. The latter has the advantage of being easily dispensed by a robot. An automated feeder would save me one chore per day, and I wouldn’t have to worry about getting home late in the evenings. It’s also very handy for travel.

After some research, I decided on this model- the PetSafe programmable automated feeder. It has a large capacity, and really extensive programming options. For cats with food-security issues (common in rescue situations) this machine can be programmed to feed in multiple stages throughout the day. Sprocket seems to be much less stressed having her dinner spread out over the course of the evening. The reviews were positive, and people also said that the cat can’t get into it to steal food.

Those people have never met Sprocket H.G. Shopcat.

If there’s one thing I learned in this odyssey, it’s that automatic cat feeders are the equivalent of giving a piece of dental floss to someone serving life in prison. With infinite time, you can escape anything, and (it turns out) break into almost any robot.

The allegedly cat-proof PetSafe food robot.

The machine has a silicone conveyor belt driven by a continuous servo. A microcontroller times the servo’s operation to control portion size. The conveyor is gravity-fed by a hopper above it. The food falls off the end of the conveyor and down a vertical chute into an attached bowl.

Sprocket’s first gambit was very simple- she would nudge the machine with her little eight pound body, and some food would fall out. There were always some loose pieces near the end of the conveyor, and jostling the machine would send a few out. The machine is under a table, so I answered this first challenge with some stiff wire to anchor it to the table leg.

Anchored to the table, now jostle-resistant. You can see I also used a binder clip to better secure the bowl. The OEM method uses a plastic tab that Sprocket defeated in 8 seconds.

Undeterred, Sprocket then learned she could climb on to the stringers of the table to get high ground above the machine, then grab the top edge with her little mouth. She could then lift it and drop it, causing pieces to fall out. To deter this, I grabbed a heavy piece of steel off the junk pile and placed it on the machine to make it hard to lift with tiny feline choppers.

Scrap steel and zip ties. Will this countermove prevent the vertical attack gambit?

This made picking up the machine inconvenient enough that she switched tactics. Her next move was to lie on her back in the bowl, and stick her paw up the chute. She could paw the conveyor belt itself, getting it to move. This was very effective, netting an extra meal or more.

Now things are getting tricky. I needed to prevent chute access by paws, while still allowing food out. The position is awkward for her, so I fabricated a straight bar across the chute opening that would divide the space in half and make it so she couldn’t get a good angle to reach the conveyor any more.

Here we are looking up into the chute. I ran a piece of 1/8″ steel rod though the plastic on either side, securing it with hitch pins.

This worked briefly, but she then returned to the lift-and-drop strategy. It turns out she’s quite strong, and managed to lift and drop the machine even with the chunk of steel on it. To combat this, I made a metal hold-down bracket out of some scrap metal and screwed it to the table. It was now physically impossible to lift the machine.

Surely this will be the end of the lift-and-drop game. I can’t even lift it now, and I’m a lot more than 8lbs.

Undeterred, she returned to attacking the chute. Her old approach didn’t work anymore, but she quickly learned she could move to the side of the bowl and get a more vertical approach angle, thus bypassing the divider bar.

For the next round, I grabbed an old plastic soda bottle, and made an extension to the chute. This completely blocked access while still allowing food to slide down into the bowl.

This worked for almost two full days, which was a record. However, she chewed doggedly at that plastic soda bottle until she had destroyed it. In celebration, she ate some large number of extra meals while I was at work, and proceeded to throw up all over the kitchen. It was the best and worst day for Sprocket.

The idea of the chute extension was sound, it was just my implementation that was flawed. The junk pile coughed up a piece of 24ga copper sheet which I used to upgrade the extension.

You can see I leveraged the divider bar as a mounting point for the copper chute extension. This is very sturdy and should finally defeat the chute gambit.

Mostly foiled by this copper, she then went back again to the lift-and-drop strategy. This time she figured out she could rotate my hold-down clamp out of the way, and again the machine was free to lift. I responded to this by putting more bends in the clamp such that it was now wrapped fully over the lip of the machine, and could not be swung out of the way.

I would say “surely this will hold”, but at this point I’ve learned not to make any predictions about Sprocket’s capabilities. You can see on the left that she has managed to paw the 2lb chunk of steel off the machine and on to the floor.

This worked for a few more days, but I was worried. She was managing to loosen the new clamp a bit over time, and I didn’t feel good that my chute extension would hold forever. She was working very hard to defeat all these new measures. What next?

Well, here at Blondihacks Labs, we know that there is no problem that can’t be solved with a lot of steel plate. Yes, it was time to go Full Furiosa on this cat feeding robot. I pulled a bunch of 1/8″ steel plate off the junk pile and got to work.

The goal was to completely enclose the machine, thus eliminating all possible access points. I also wanted a system that would completely restrain the bowl, and restrict access to the front part of it (to protect the chute area). The reason for using 1/8″ steel is that the resulting box will be so heavy as to be utterly out of the question for an 8lb mammal to effect change upon it in 3D space.

I found some foam core on the junk pile next to the steel, so I opted to use that to mock up the pieces I would need.

Next up, tracing and cutting the major pieces. This scrap has a big nasty bend in it, so I’m laying my pieces out around that as best I can.

Here’s the first test fit of the sides and back. Looking good! Time to start tacking things together.

You might say this bump-out on the front is because I mis-measured the length of the top section of the machine. On the contrary, it’s a stylish bit of art deco detailing. No, definitely not because I measured wrong. Definitely not that.

Despite my Furiosic zeal to armor the hell out of this thing, I do also need it to be functional. That means it needs a lid that I can open. The junk pile provided some nifty friction hinges that I think were left over from one of the failed Teddy Top iterations. They’ve been waiting in The Pile for their moment to shine!

They’re sturdy hinges, but a bit too small to bolt in place- there wasn’t enough material on the side for mounting holes, due to the thickness of the lid and small size of the hinge plates. I opted to use the screw holes to plug-weld the hinges in place. This was tricky, because they are very thin material. They’re also galvanized, so don’t breathe the green smoke. I wear a respirator when I weld anyway, but still, zinc fumes are turbo-nasty for you.

To eliminate a prime feline entry vector, I needed a secure closure. I added some tabs and tapped them for M6 bolts. These are finger-tightened in place, which makes opening the lid for refilling food easy. You need opposable thumbs to remove a bolt (even a finger-tight one), so I’m confident this is secure.

All the major seams are fully welded up now, and things are looking good. Next up is the bowl restraint. The front edge of the box holds the top of the bowl down, but we need more.

I wasn’t taking any chances with the bowl, because it’s potentially a huge weak link in the system. If she gets that loose, all is lost. She’ll be able to get any angle she wants on the chute, and it’ll be cat vomit as far as the eye can see.

I made an integral band around the front of the bowl using the MAPP gas torch bending technique I’ve talked about before on this blog.

I took the extra step of drilling the front of the bowl and securing it to the metal band with stainless steel hardware (for food safety).

In that photo, you can also see the copper chute control. The idea here is to have an adjustable section on the front that I can modify as needed. I need the system to be such that she can reach all parts of the bowl with her paw, but not be able to reach upwards towards the chute in any way. The front edge of this copper shield is rolled upwards to make a soft lip, since her head and paws will be all up in there. The copper is easily removable in case I need to make modifications, or if she somehow destroys it and it needs replacing or repair. I tried to keep all areas that might contact the food copper or stainless.

I spent a lot of time sanding, filing, and polishing every corner and edge on this thing. I wanted to be sure there was no chance of her cutting herself if she rubbed, chewed, or pawed at any part of this box. This thing is so comfortable and safe to touch that you could roll it around on balloons and nothing would pop.

You might also notice in that last photo that it has a stylish old-timey patina. I hit it with JAX metal blackener instead of paint because I was afraid if she chewed on it, she would scrape paint off and get it in her little system. This seemed safer. Honestly, being steel, she has shown no interest in even touching it, never mind chewing or rubbing on it. Still, better safe than sad kitty.

The whole thing came out very unintentionally steampunk-looking, because of the patina, the copper, and the regularly-spaced bolts. All it’s missing is a few gratuitous gears. Maybe it should be called Professor Quinn’s Fantastic Patented Cat Confabulator.

The final security measure is to place the machine on a rubber sheet. This protects my cheap laminate from the steel, but also makes the machine immovable. Even something heavy can be slid around if the surface is low-friction, so I made it as high-friction as possible. The rubber sheet is actually a dog bowl mat. Don’t tell Sprocket- the indignity of that might be too much to tolerate. She might retaliate by chewing through the gas line on the dryer or something.

Moment of truth time. Does it work?

As you can see below, the copper shield is doing its job. She can still paw the food forward from the back of the bowl, which is actually a nice activity for her. Making dinner a project for cats is a good thing- keeps them occupied, and keeps them from eating too fast.

Interestingly, Sprocket has shown zero interest in probing this new feeder for weaknesses. It’s almost as though there’s a psychological effect of the imposing structure that is keeping her from even trying.

A friend noticed that the machine ended up with quite an art deco feel to it, so she made a logo for the front. I think it finishes things off nicely.

It’s the little things.

You might say I’ve won this battle. However I just spent 20 hours armor-plating a cat feeder. I think we know who’s really in control here, don’t we?

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71 thoughts on “Furiosa’s Cat Feeder”

Ooh, I see a problem. Insulate that steel and that copper from each other, posthaste — lest the words “galvanic corrosion” give you mayhem and strife 😉 some rubber or plastic grommets will do you nicely — and even if Sprocket chews through the grommets, the bolts are metal and therefore significantly less chew-through-able. The worst she can do is annoy you…

An electrolyte is required, but not very much. Moisture condensed from the air will do, or cat slobber, or spray (but she wouldn’t do that as a girl). Boiling water on a cold morning is probably your greatest threat to it.

The real problem is the issue of the challenge you presented. Most cats are smart, and Sprocket seems typical, and humans are not to be allowed to win. I have had cats in my life since around 19xx, and the received wisdom is that you can leave a big pile of food out, and the won’t over eat. We feed our five dry food all day, and only one eats more than he should, but still not enough to cause digestive distress. There is a classic device for use when going on vacation that has a bowl attached to a half gallon wide mouth jar, that gravity fills the bowl as it is emptied. When a friend tried one years ago, the first filling was emptied by paw, so all the food was piled around the bowl and scattered around the kitchen. After the next filling, the food mostly stayed in the bowl. The dog equivalent was only on the market for about a month. Dogs will eat a 50 pound bag of chow in one sitting, with short breaks to make the tummy feel better.

Anyway, you have created another masterpiece, and I look forward to the next time you butt heads with Sprocket.

She’s less likely to spray as a girl but I’ve actually had mine spray a little when stressed (usually after a move). I’m just glad that with our four cats we haven’t had to do anything like this to deter over-eating. We’ve got a much less armored feeder that gives them 4 smallish meals a day and they seem to love it. We do also regularly give them wet but with 4 cats supplimenting that with some good dry food helps a lot. It also helps because one of our cats actually gets an upset stomach on only wet food (surprisngly, the pickiest of the eaters).

So we’re doing the old “anecdote as fact” thing?I’ve had an unbroken line of cats share whatever passed for a home at the time for well over 40 years, so I must be an unquestionable expert.

The idea that cat’s won’t overeat is laughable. Many cats overeat if given the chance, some pathologically so. It’s a very serious health risk to pet cats; ask a vet some time if you doubt it, or google. And I’ve had numerous gravity fed feeders over the years; while convenient, they provided precisely zero deterrent to a cat that already overate.

Also, *all* cats can and do spray. Once again, you could google it. I once got a completely new living-room set and both female cats sprayed it a couple of times; I assume to make it smell ‘right’. I had a female cat who would spray my then girlfriends bike every time she brought it in the house (marking territory, I guess). I even had one female tabby who would back up and spray directly on my leg when she was really annoyed (like the time someone brought a dog over unannounced). That cat was above average weird, tho, and not just for that.

Some cats self-regulate; I’ve been lucky enough that every cat I’ve had has been like this. But I’ve seen other people’s cats that do – and do so A LOT.

I’m sure there’s a correlation to past experiences of food insecurity (for rescue cats), but the reaction to those experiences can be very idiosyncratic. My cat, for example, reacted by being *excessively* self-regulating – as soon as her food bowl gets down to even half-empty, she basically stops eating until it’s refilled, or she’s very very hungry. Never know where the next meal’s coming from, after all.

Anyway, self-regulated eating is a very big factor for me in choosing a cat; reduces the workload a LOT.

i have 2 cats, one is a very chubby 3 year old floof, but i also have a rather skinny 14 year old kitty who seems to have chronic digestive issues. the latter kitty benefits from an open bowl so that he can eat when he feels up to it. unfortunately it has allowed the former kitty to reach astronomical proportions. ive been trying to ration out the food better, but it seems like the fat kitty always eats most of it. any attempt at differential feeding will likely result in strife and misery for the cat butlerey staff. sometimes its better just to give them what they want and walk away slowly.

look for the Petsure feeding bowls that open in reaction to the cat’s microchip….and close when it is shoved out of the way by the greedy fat brother (oh, sorry, no that bit’s not on the box…but it’s how it works round us!)

Sorry to be something of a pest… but my inbox is currently blowing up like a hundred thousand sticks of dynamite, and I can’t make it stop… mostly because I subscribed when I posted, so I’d see the reply before sometime in the 22nd Century 😉

I want to unsubscribe, now, but I can’t figure out how — the “manage your subscriptions” link goes to an empty blog post with nothing in it and comments disabled… momentarily turning off Adlbock Plus doesn’t help.

Also, Quinn (or do you prefer Ms. Dunki?), a polite suggestion for future coding — there ought to be a way to subscribe to a single comment /thread/ and not receive an electronic avalanche when the comment section gets popular, because the system sends an email for every single comment made on the post “liek evar” 😉 I’m just sayin’. (To be fair, Hackaday has that same problem, so it may be a WordPress bug. Dunno.)

It happens… in the grand scheme of things it’s barely there. I can handle a few spurious emails… the Insert key on this laptop may have fallen off, but the Delete key is most certainly still there 😉

Mostly it’s my fault, though, since I was dumb enough to subscribe even though I pretty well knew what the result would be, lol…

Thanks for doing a little midwinter cleanup, though — I saw the “closed for maintenance” sign 😉 If you reply to me, and you don’t get further response (at least for a while), it almost certainly worked…

Also — just for the record — I was somehow under the impression that you knew some Web code stuff…? Might’ve been my imagination, though. My memory — even at the best of times — is somewhat like a sieve… one that’s been punched through 😛 don’t get me wrong, it’s still all there, it’s just got a big hole in it!

I am so impressed by your determination and how much you care for your cat! But you might want to look into the fact that cats are designed to get all their water from their food, and ditch the dry food altogether. Although there are certainly vets who feel that dry food is superior, and I assume you will consult the oracle Google to research this, you might want to start here: http://pets.webmd.com/cats/guide/mistakes-people-make-feeding-cats?page=2.
That said, a handsome container indeed for your autofeed machine.

@forrest: London time is not UTC, it is GMT, the G stands for Greenwich, which is actually here in the southwest. It just happens to coincide with UTC for 6 months a year. London actually changes time zones to accommodate daylight savings time, it changes to something called BST OR British Summer Time. We had a long discussion about this at work (I’m an iOS developer) because we had some issues with time logging between the app and the servers, had to do our homework. GMT is a time zone, UTC is not, it’s a time standard. No country uses UTC as local time.

Next thing Sprocket will do is learn to use a plasma cutter and attack that shielding Simon’s cat style ^_^

I think the original deign flaw is that it let the food smell out.
I have no idea how difficult it would be to make that feeder smell-tight, but I believe your four pawed friend would be way less persistent at attacking that thing if it doesn’t smell like food.

Yah she can definitely smell the food in it. I feel like my enclosure hasn’t fixed that really. The chute is still open to the air. It’s possible I’ve muted the smell enough that it doesn’t make her crazy anymore?

I’ve got a different feeder (a PetMate unit) that we only use for vacations, but it has similar problems. I’ve been thinking that the way to deal with it is to get a candy machine head, mount it to a relatively tall chute (higher than kitty’s limb length), and use a micro and a gear motor to turn it on an appropriate schedule.

Honestly, I’m not much of a welder. Luckily you can still get stuff done despite that.

An alternative to height that you might consider is finding a way to add an S bend to the scoop. Either with an extension of some sort or modifying the original. A S bend should block access without obstructing food.

Bought the same feeder. Had the SAME issues. We have our feeder backed into a corner and no access to shop tools of any kind. I’ve put the feeder on a high-friction dog mat as well and we stuck a 40lb litter box on top of it. She was nudging it to the point of not actually receiving her meals because she was pushing food the wrong way down the conveyor, so it ended up having the opposite effect but her little walnut brain couldn’t understand that.

We also got her one of those spiky food bowls so she is more preoccupied with trying to nudge the bowl out of the way (to get her food easier/faster), she bothers with the machine much less now, but still. I’ve been so close to screwing the damn thing into the wall.

Nice job and incredible cat you have!! What worked for our cats was the pipolino which is wayyy more on the low tech side of things. http://www.pipolino.eu/en/ this has also the benefit of giving them food all day long which in turn reduces their stress of not having food available.

The only possibly-simpler solution I can think of for now is elevating the cat feeder and elongating the chute to prevent kibble splatter. But that assumes you would have the space for that set-up, and Sprocket wouldn’t rage-push the machine off the ledge…which might be too big of an assumption. Plus, you now have an armored steampunk kibble droid!

Regardless, this story is amazing, you’re amazing, Sprocket is amaaaaaazing.

We also have an automatic biscuit feeder. Every time we go shopping and buy biscuits we put them on a shelf in the garage where the cats live. By morning it will be on the floor ripped open (even if there is ALREADY a ripped open bag on the floor) . This not only makes a very convenient automatic feeder for our three pecan brained pussies but is also a really handy automatic, all you can eat for free, open buffet for any passing dog, duck, chicken, goose, goat sheep, cow (not ours, escapees from next door) or feral cat which might just happen to be passing and feel like a little smidgen of something, isn’t that GREAT!! It’s so convenient. And from the cat’s point of view it means they never have to put up with the same tasting food for more than about two meals, EVEN BETTER! I think this is the perfect system (for the cats, dogs, ducks, old uncle tom Cobbly and all etc) We used to keep the biscuits in a plastic bin with a flip top lid which the cats opened and then lost so they could stick their paws in and scoop out the biscuits but they found this not as convenient as the Al fresco method so they made sure the plastic container was disappeared one dark night. PS I haven’t yet caught Bill Brewer, Jan Stewer, Peter Gurney, Peter Davy, Danl Whiddon, Arry Awke, old uncle Tom Cobbly and all in there yet but be assured the day I do, they (and the horse they rode in on) will become tasty morsel sized bites for the rest of the legitimate menagerie. Loved your post, keep it up! 🙂

I like your solution. Your journey was very similar to mine. Our walnut-brain also learned to knock over the whole thing, so the first response was a bungy cord to a shelving unit. Then she learned to reach up, into the spout, so we added a plywood enclosure. But she chewed the plywood to get access, so we added an aluminum edge. She’s given up the quest for now.

If the food is dispensed by a timed conveyor belt and the only food stolen by the cat came from what was left on the conveyor belt, then this amount would simply be lacking in the next distribution of food. There is no net change in food received by the cat, making all modifications unnecessary.

Well done! In some of the photos, it looks glossy black, but I don’t think it’s painted, is it? If not, I think it would look great with a lacquered glossy black finish.

I wonder if the side edges of the copper baffle might still be a bit dangerous, as a finger/claw trap.

I have tried a few commercial automated cat feeders, and my cats have defeated most of them, prising open lids, driving rotors forward, knocking hoppers over, etc. Currently Bongo gets his dry food when we go away for a weekend from a cheap gravity hopper. As supplied, Bongo could knock it over and open the reservoir, so I drilled it down the vertical axis and bolted it to a 500×500 board. The board stops it from being knocked over, and the bolt holds the reservoir to the bowl. He gets as much as he wants, luckily he is not an overeater.

I too have had to do major operations to counter a cat’s whims. We could handle finding mouse heads, bits of guts and stuff, but the dealbreaker was when we found a rat in the library. It had turned into an ecosystem. So we installed internal human-sized doors and one way flaps to let him out, but not back in without being vetted. Although he has still managed to bring a rat in – he hid it when he yowled for admission, then picked it up when the door was opened. What an arsehole.

“A veterinarian who specializes in behavioral medicine, [Vint] Virga has treated many household pets in his clinic. He deals with such issues as appetites, anxiety and obsessive behavior.

“On making cats forage for food

“Probably the most important thing I stress to all my clients is to think about what the cat would do if they were living in nature. I take my clients through a program of actually teaching their cats to forage for their food.”

It’s from the U.S. National Public Radio program “Fresh Air”. Most excellent.

Had a similar problem. Raccoons would get through the Micro chip triggered cat flap, (that’s another story) then raid the cat feeding machine. Flipping it upside down and emptying the hopper on the ground in our patio. I armored that feeder inside a 3/4″ ply box screwed to the wall. which worked. There is a fix for the cat flap now which locks it when a non recognized or wrong chipped beastie / raccoon(s) tries to enter, but I think that would mean a new cat flap. But raccoons are very strong and I did notice bits of cat flap outside the patio and walked in on a Raccoon who stared me out and then nonchalantly went on his way with an air of superiority that shames me to this day. :0

Not sure if this was mentioned in the other comments, but the problem with just leaving a big bowl of food out for your cat to graze on is rodents and insects. They love the cat (and dog) kibble.

I applaud you for not finally giving in and succumbing to your feline master as we have – our daily hours are marked by when the pets want their food, and we obligingly scoop and provide it to them. Saves us money otherwise wasted on vacations, day trips and other frivolities that would prevent us from dutifully serving them.

I showed this article to my 16-year-old daughter who is in charge of our cats. We have a rescue that was dumped out here in Indiana cornfield country in the middle of a 10-day stretch of sub-zero weather a couple of years ago. The poor thing was painfully thin and was probably dumped because she had gone into her first heat. That cat would probably rival Sprocket for ingenuity and food motivation.

Ever wanting to encourage math in my math-avoiding daughter (and show her that math can help one make decisions), I pointed out the absurdity of the 20+ hours spent working on modifications. Then I showed her how funny it was:

20 hours = 72000 seconds
Generously, it probably takes 15 seconds to scoop and pour an evening meal of dry food.
72000 seconds divided by 15 seconds = 4800 feed sessions in that 20 hours.
With 365 evening dinners a year, those 4800 sessions equate to 13.15 years of feedings.
At 10 seconds to scoop and pour, it equates to 19.73 years.
At 5 seconds, it’s 39.45 years.

My point to her was that by making the modifications, the cat’s servant did not save any time. Then my daughter pointed out the intangible but very valuable amusement factor, and I gave up. 🙂

There’s also the fact that, well, your math is misapplied. It’s not _wrong_ (I’m sure, I didn’t double-check the figures), but it misrepresents the problem at hand. The feeder was never claimed to be a time-saving device, since as you point out feeding a cat takes very little actual TIME. The actual stated intent was:

“An automated feeder would save me one chore per day, and I wouldn’t have to worry about getting home late in the evenings. It’s also very handy for travel.”

20+ hours of work (not even counting the time spent photographing the various mods and documenting them here, which is additional time “lost” to the project in your formulation) to relieve the scheduling pressure of a daily time commitment can be a great bargain, even if — especially if! — that scheduled activity takes mere seconds to complete.

Not to mention your daughter’s excellent point about the relative intangible value of the tasks. 20+ hours of stimulating work attacking a problem, vs. 15 seconds a day of utterly unfulfilling tedium, is an easy call for anyone who enjoys this sort of thing.

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